Perioperative circulating tumor cells in surgical patients with non-small cell lung cancer: does surgical manipulation dislodge cancer cells thus allowing them to pass into the peripheral blood?

Circulating Tumor Cells from Surgical Manipulation Predict Recurrence and Poor Prognosis in Non-Small Cell Lung Cancer

Background/Objectives: In our previous multicenter prospective controlled study (UMIN000018602), we investigated the impact of surgical manipulation on circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). CTCs were detected after surgery in four patients (4/29, 13.8%), although CTCs were not present before surgery. These four patients had tumor cells leaked into their bloodstream by surgeons' manipulation. We aimed to clarify long-term outcomes according to the presence of CTCs. Methods: Patients with cT1b-2N0M0 NSCLC scheduled for lobectomy were enrolled, based on the selection criteria of a consolidation-to-ground-glass opacity ratio (over 50%). Peripheral blood samples (≥3 mL) were collected before surgery (for pre-CTCs), during surgery, and immediately after pulmonary vein dissection (for post-CTCs). CTCs were isolated from these samples using ScreenCell®'s size-selective method. Results: From July 2015 to January 2016, 29 patients were enrolled, yielding paired pre- and post-CTC samples for all patients. Thirteen patients were pre-CTC positive, and post-CTCs were detected in 17 patients. Survival analysis revealed a statistically significant difference in recurrence-free survival between patients with and without post-CTCs (p = 0.043), while pre-CTCs status had no significant impact on recurrence (p = 0.226). Patients with post-CTCs had a significantly higher recurrence rate than those without (p = 0.043). Half of patients with post-CTCs but without pre-CTCs had recurrence within 5 years after surgery. Conclusions: Post-CTCs emerged as a significant predictor of recurrence following lobectomy; however, it could be possible for thoracic surgeons to prevent recurrence by improving surgical techniques for NSCLC patients with post-CTCs but without pre-CTCs.

Circulating tumor cells: from new biological insights to clinical practice

The primary reason for high mortality rates among cancer patients is metastasis, where tumor cells migrate through the bloodstream from the original site to other parts of the body. Recent advancements in technology have significantly enhanced our comprehension of the mechanisms behind the bloodborne spread of circulating tumor cells (CTCs). One critical process, DNA methylation, regulates gene expression and chromosome stability, thus maintaining dynamic equilibrium in the body. Global hypomethylation and locus-specific hypermethylation are examples of changes in DNA methylation patterns that are pivotal to carcinogenesis. This comprehensive review first provides an overview of the various processes that contribute to the formation of CTCs, including epithelial-mesenchymal transition (EMT), immune surveillance, and colonization. We then conduct an in-depth analysis of how modifications in DNA methylation within CTCs impact each of these critical stages during CTC dissemination. Furthermore, we explored potential clinical implications of changes in DNA methylation in CTCs for patients with cancer. By understanding these epigenetic modifications, we can gain insights into the metastatic process and identify new biomarkers for early detection, prognosis, and targeted therapies. This review aims to bridge the gap between basic research and clinical application, highlighting the significance of DNA methylation in the context of cancer metastasis and offering new avenues for improving patient outcomes.

The impact of vascular division sequence and epithelial-mesenchymal transition status on postoperative recurrence in lung adenocarcinoma

BACKGROUND

The vascular division sequence in video-assisted thoracic surgery (VATS) lung resection is usually determined by the handling difficulty due to the limited surgical view through the scope. However, upfront pulmonary vein division is theoretically desirable to avoid tumor cells spreading by surgical manipulation. Epithelial-mesenchymal transition (EMT) is associated with poor prognosis and an increased number of circulating tumor cells. The purpose of this study is to evaluate the effect of vascular division sequence and EMT on postoperative recurrence.

METHODS

We retrospectively investigated tissue microarrays of 282 lung adenocarcinomas surgically resected between 2001 and 2007. We excluded the cases with segmentectomy, wedge resection, dissemination, insufficient material for staining, or lack of medical records. The effect of vascular division sequence and clinicopathologic factors on recurrence was evaluated in 195 cases.

RESULTS

The upfront pulmonary vein division (V-first) was performed in 60 patients, and the upfront pulmonary artery division (A-first) was performed in 135 patients. The recurrence was observed in 67 patients (13 in V-first and 54 in A-first). Epithelial-mesenchymal transition activation was observed in 104 patients. Multivariable analysis with 195 patients revealed that lymph node metastasis and pleural invasion were risk factors for the recurrence. The stratified multivariable analysis showed that vascular division sequence (A-first) was a risk factor only in the EMT-negative group (91 patients). In the EMT-negative subset, the 5-year relapse-free survival rate was significantly lower in the A-first group than the V-first group (72.6% vs. 92.2%, p  =  0.0136).

CONCLUSIONS

The upfront pulmonary artery division might be a risk factor in patients without EMT activation.

Circulating biomarkers in perioperative management of cancer patients

Owing to the advances in surgical technology, most solid tumours can be controlled by surgical excision. The priority should be tumour control, while some routine perioperative management might influence cancer progression in an unnoticed way. Moreover, it is increasingly recognized that effective perioperative management should include techniques to improve postoperative outcomes. These influences are elucidated by the different functions of circulating biomarkers in cancer patients. Here, circulating biomarkers with two types of clinical functions were reviewed: (i) circulating biomarkers for cancer progression monitoring, for instance, those related to cancer cell malignancy, tumour microenvironment formation, and early metastasis, and (ii) circulating biomarkers with relevance to postoperative outcomes, including systemic inflammation, immunosuppression, cognitive dysfunction, and pain management. This review aimed to provide new perspectives for the perioperative management of patients with cancer and highlight the potential clinical translation value of circulating biomarkers in improving outcomes.

Risk factors for postoperative cerebral infarction in Lung Cancer patients: a retrospective study

BACKGROUND

Postoperative cerebral infarction is a rare but serious complication after lung cancer surgery. We aimed to investigate the risk factors and evaluate the efficiency of our devised surgical procedure to prevent cerebral infarction.

METHODS

We retrospectively examined 1,189 patients who underwent a single lobectomy for lung cancer at our institution. We identified the risk factors for cerebral infarction and investigated the preventive effects of performing resection of the pulmonary vein as the last step of the surgical procedure during left upper lobectomy.

RESULTS

Among the 1,189 patients, we identified 5 male patients (0.4%) with postoperative cerebral infarction. All five underwent left-sided lobectomy including three upper and two lower lobectomies. Left-sided lobectomy, a lower forced expiratory volume in 1 s, and lower body mass index were associated with postoperative cerebral infarction (Ps < 0.05). The 274 patients who underwent left upper lobectomy were stratified by two procedures: lobectomy with resection of the pulmonary vein as the last step of the surgical procedure (n = 120) and the standard procedure (n = 154). The former procedure significantly shortened the length of the pulmonary vein stump when compared with the standard procedure (mean stump length: 15.1 vs. 18.6 mm, P < 0.01), and the shorter pulmonary vein might possibly prevent postoperative cerebral infarction (frequency: 0.8% vs. 1.3%, Odds ratio: 0.19, P = 0.31).

CONCLUSIONS

Resecting the pulmonary vein as the last step during the left upper lobectomy enabled the length of the pulmonary stump to be significantly shorter, which may contribute to preventing cerebral infarction.

Pure Solid Pattern of Non-Small Cell Lung Cancer and Clustered Circulating Tumor Cells

There are two solid patterns of non-small cell lung cancer (NSCLC) on computed tomography (CT): pure or mixed with ground-glass opacities (GGOs). They predict the degree of invasiveness, which may suggest the presence of clustered circulating tumor cells (CTCs), a predictor of poor prognosis. In this study, we assessed the implications of the solid patterns on CT and the preoperative clustered CTCs in surgically resected NSCLC. CTCs were detected using a size selection method. The correlation between the presence of preoperative clustered CTCs and the solid pattern and the prognostic implications were evaluated using co-variables from the clinical-pathological findings. Of the 142 cases, pure solid lesions (Group PS) and mixed GGOs (Group G) were observed in 92 (64.8%) and 50 (35.2%) patients, respectively. In Groups PS and G, clustered CTCs were detected in 29 (31.5%) and 1 (2.0%) patient (p < 0.01), respectively. The PS appearance was an independent predictor of preoperative clustered CTCs in the multivariable analysis, and preoperative clustered CTCs were an independent predictor of poor recurrence-free survival; the solid pattern was not an independent variable. Thus, the PS pattern of NSCLC on CT is an indicator of preoperative clustered CTCs, which is an independent poor prognosis predictor.

Circulating Tumor Cells and the Non-Touch Isolation Technique in Surgery for Non-Small-Cell Lung Cancer

Circulating tumor cells (CTCs) are dislodged from the primary tumor into the bloodstream, travel within the bloodstream to distant organs, and finally extravasate and proliferate as epithelial metastatic deposits. The relationship between the existence of CTCs and tumor prognosis has been demonstrated by many researchers. In surgery for malignancies, the surgical manipulation of tumors and tissues around the tumor may lead to the release of CTCs into the bloodstream. The non-touch isolation technique (NTIT) has been advocated to prevent the release of CTCs during surgery. The concept of NTIT is the prevention of intraoperative increment of CTCs from the primary tumor by the early blockade of outflow vessels, and ‘pulmonary vein (PV)-first lobectomy’ during surgery for non-small-cell lung cancer (NSCLC) corresponds to this technique. The concept of PV-first lobectomy is well known among thoracic surgeons, but evidence of its efficacy for preventing the increase of intra- and postoperative CTCs and for improving postoperative prognosis is still uncertain. Our study summarizes evidence regarding the relationship between NTIT and CTCs in NSCLC and suggests the need for further research on CTCs and CTC-detecting modalities.

aBVA Procedure by Uniportal Video-Assisted Thoracoscopic Surgery for Right Upper Peripheral Lung Cancer: A Randomized Trial

Objective

This study aims to determine the optimal dividing order of anatomic pulmonary resection under uniportal video-assisted thoracoscopic surgery (uni-VATS) for patients with right upper peripheral lung cancer.

Methods

Patients who met the eligibility criteria were randomly allocated into the aBVA and VAB groups. In the aBVA group, the surgical procedure proceeded from the posterior to the anterior region (from the deeper to the superficial site). In the VAB group, the dissection orders were vein first followed by arterial branches, followed by the bronchus. Clinical data were collected and analyzed.

Results

Sixty patients were randomly allocated to the aBVA group (n = 30) and the VAB group (n = 30). The operation time in the aBVA group (230.500 ± 68.360 min) was significantly shorter than that in the VAB group (305.600 ± 107.821 min) (p = 0.01). The blood loss in the aBVA group (104.000 ± 70.935 ml) was significantly lower than that in the VAB group (391.000 ± 625.175 ml) (p = 0.01). Two patients in the VAB group underwent conversion to 2-portal VATS. The number of lymph nodes (13.367 ± 5.436 vs. 10.333 ± 7.279, p = 0.072) and lymph node stations (5.067 ± 1.574 vs. 4.467 ± 2.345, p = 0.567) were comparable between the two groups. The differences in the postoperative drainage tube time (5.033 ± 3.113 vs. 6.467 ± 4.447 days, p = 0.278) and hospital stay (8.233 ± 3.390 vs. 9.433 ± 4.523 days, p = 0.361) were not significantly different between the two groups.

Conclusion

Compared with the VBA procedure, aBVA is easier for patients with right upper peripheral lung cancer who undergo uni-VATS lobectomy.

Vein-first Lobectomy for Lung Cancer Assessed According to the Status of Clustered Circulating Tumour Cells

BACKGROUND/AIM

Vein-first lobectomy (VFL) in lung cancer might reduce shedding of circulating tumour cells (CTCs). This study assessed the clinical significance of VFL.

PATIENTS AND METHODS

Lung cancer patients undergoing lobectomy and CTC testing were evaluated. The primary evaluation item was postoperative clustered CTC detection, and the secondary outcome measures were the 2-year overall survival and recurrence-free survival rates according to the status of VFL and postoperative clustered CTC.

RESULTS

Eighty-six patients with similar backgrounds, except for lobe resection and pulmonary vein dissection time, showed postoperative clustered CTC identification rates of 43.8% and 37.9% in the VFL group (n=57) and no-VFL group (n=29), respectively. However, prognosis was not significantly different, although the presence of clustered CTC after surgery was a predictor of recurrence.

CONCLUSION

The status of postoperative clustered CTC was similar regardless of VFL or not, although the detection of clustered CTC was a predictor of recurrence.

Anesthetic Propofol Promotes Tumor Metastasis in Lungs via GABAA R-Dependent TRIM21 Modulation of Src Expression

Generation of circulating tumor cells (CTCs), a key step in tumor metastasis, occurs during surgical tumor resection, often performed under general anesthesia. Propofol is the commonly used anesthetic, but its effects on CTCs and tumor metastasis remain largely unknown. Propofol effects are investigated in an experimental metastasis model by injecting tumor cells and, subsequently, low- or standard-dose propofol to nude mice through tail vein. Propofol- or vehicle-treated tumor cells are also injected to the mice. An in vitro tumor cell-vascular endothelial cell adhesion assay, immunofluorescence, and other methods are employed to assess how propofol affects tumor cell adhesion and extension. Propofol induces more lung tumor metastasis in mice than control. Mechanistically, propofol enhances tumor cell adhesion and extension through GABAA R to downregulate TRIM21 expression, leading to upregulation of Src, a protein associated with cell adhesion. These results demonstrate that propofol may promote tumor metastasis through GABAA R-TRIM21-Src mechanism.

Clinical significance of circulating tumour cells and Ki-67 in renal cell carcinoma

Background

Renal cell carcinoma (RCC) is a common malignant tumour of the genitourinary system. We aimed to analyse the potential value of metastasis-related biomarkers, circulating tumour cells (CTCs) and the proliferative marker Ki-67 in the diagnosis of RCC.

Methods

Data from 24 laparoscopic radical nephrectomies (RNs) and 17 laparoscopic partial nephrectomies (PNs) were collected in 2018. The numbers and positive rates of CTCs and circulating tumour microemboli (CTM) in the peripheral blood were obtained at three different time points: just before surgery, immediately after surgery and 1 week after surgery. Ki-67 protein expression was evaluated in the RCC tissue by immunohistochemistry.

Results

Except for the statistically significant association between the preoperative CTC counts and tumour size, no association between the number and positive rate of perioperative CTCs and clinicopathological features was found. The CTC counts gradually decreased during the perioperative period, and at 1 week after surgery, they were significantly lower than those before surgery. High Ki-67 expression was significantly positively correlated with preoperative CTC counts. In addition, Ki-67 expression was higher in the high CTC group (≥ 5 CTCs).

Conclusion

Our results suggest that surgical nephrectomy is associated with a decrease in CTC counts in RCC patients. CTCs can act as a potential biomarker for the diagnosis and prognosis of RCC. A careful and sufficient long-term follow-up is needed for patients with high preoperative CTC counts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02268-5.

The sequence of pulmonary vessels ligation during lobectomy for non-small cell lung cancer: A systematic review and meta-analysis

OBJECTIVES

The effects of ligating the pulmonary vein first or pulmonary artery first during lobectomy on the long-term survival of patients with non-small cell lung cancer (NSCLC) remain controversial. We conducted the first systematic review and meta-analysis to determine the association between different sequences of vessel ligation during lobectomy and the prognosis of patients with NSCLC.

METHODS

Literature retrieval was performed by systematically searching Embase, PubMed and Web of Science to identify relevant articles published from the inception of each database to November 2020. The overall survival (OS) and disease-free survival (DFS) of patients treated with vein-first ligation versus those treated with artery-first ligation during lobectomy were analyzed. A standard fixed-effect model test (Mantel-Haenszel method) was used to calculate pooled hazard ratios (HRs) and 95% confidence intervals (CIs). Heterogeneity was assessed using the Q-test and I²-test. Sensitivity analysis was performed to further examine the stability of pooled HRs.

RESULTS

Five studies with a total of 1109 patients receiving lobectomy, including one randomized controlled trial and four retrospective studies, were included in this meta-analysis. The results showed that patients with vein-first ligation had a significantly better OS (HR 1.25, 95% CI 1.03-1.50; P = 0.02) and DFS (HR 1.54, 95% CI 1.16-2.04; P = 0.003) than those with artery-first ligation during lobectomy. Significant heterogeneity and publication bias were not observed during analysis.

CONCLUSION

Our meta-analysis indicates that vein-first ligation may improve the prognosis of NSCLC patients receiving lobectomy. Therefore, vein-first ligation is recommended during lobectomy for patients with non-small cell lung cancer whenever possible.

Patterns and timing of perioperative blood transfusion and association with outcomes after radical cystectomy

BACKGROUND

Perioperative blood transfusion (PBT) has been associated with worse outcomes across tumor types, including bladder cancer. We report our institutional experience with PBT utilization in the setting of radical cystectomy (RC) for patients with bladder cancer, exploring whether timing of PBT receipt influences perioperative and oncologic outcomes.

METHODS

Consecutive patients with bladder cancer treated with RC were identified. PBT was defined as red blood cell transfusion during RC or the postoperative admission. Clinicopathologic and peri and/or postoperative parameters were extracted and compared between patients who did and did not receive PBT using Mann Whitney U Test, chi-square, and log-rank test. Overall (OS) and recurrence-free survival (RFS) were estimated with the Kaplan Meier method. Univariate/multivariate logistic and Cox proportional hazards regression were used to identify variables associated with postoperative and oncologic outcomes, respectively.

RESULTS

The cohort consisted of 747 patients (77% men; median age 67 years). Median follow-up was 61.5 months (95% CI 55.8-67.2) At least one postoperative complication (90-day morbidity) occurred in 394 (53%) patients. Median OS and RFS were 91.8 months (95% CI: 76.0-107.6) and 66.0 months (95% CI: 48.3-83.7), respectively. On multivariate analysis, intraoperative, but not postoperative, BT was independently associated with shorter OS (HR: 1.74, 95% CI: 1.32-2.29) and RFS (HR: 1.55, 95%CI: 1.20-2.01), after adjusting for relevant clinicopathologic variables. PBT (intra- or post- operative) was significantly associated with prolonged postoperative hospitalization ≥10 days.

CONCLUSIONS

Intraoperative BT was associated with inferior OS and RFS, and PBT overall was associated with prolonged hospitalization following RC. Further studies are needed to validate this finding and explore potential causes for this observation.

Preoperative Folate Receptor-Positive Circulating Tumor Cell Level Is a Prognostic Factor of Long Term Outcome in Non-Small Cell Lung Cancer Patients

Background

Surgical resection is often the preferred treatment for non-small cell lung cancer (NSCLC) patients. Predictive biomarkers after surgery can help monitoring and treating patients promptly, so as to improve the clinical outcome. In this study, we evaluated one potential candidate biomarker, the folate receptor-positive circulating tumor cell (FR⁺CTC), by investigating its prognostic and predictive significance in NSCLC patients who underwent surgery.

Methods

In this prospective, observational study, we enrolled NSCLC patients who were eligible to receive surgery. Prior to operation, peripheral blood was collected from each patient for an FR⁺CTC analysis. FR⁺CTCs were isolated by negative enrichment using immunomagnetic beads to deplete leukocytes and then quantitatively detected by a ligand-targeted polymerase chain reaction (PCR) method. These patients were then given standard care and were actively followed up for seven years. At the end of the follow-up period, the association between the FR⁺CTC level and the prognosis in these patients was evaluated.

Results

Overall, preoperative FR⁺CTC level was not significantly different among NSCLC patients with adenocarcinoma or non-adenocarcinoma subtypes (P = 0.24). However, between patients with low- and high-risk pathological adenocarcinoma subtypes, the preoperative FR⁺CTC level was significantly different (P = 0.028). Further, patients with lower preoperative FR⁺CTC level had longer relapse-free survival (RFS) and overall survival (OS) than those with higher preoperative FR⁺CTC level (RFS: not reached vs. 33.3 months, P = 0.018; OS: not reached vs. 72.0 months, P = 0.13). In a multivariate COX regression analysis, FR⁺CTC level (HR = 4.10; 95% CI, 1.23–13.64; P=0.022) and pathological stage (HR = 3.16; 95% CI, 1.79–10.14; P = 0.0011) were independent prognostic factors of RFS. Moreover, FR⁺CTC level together with adenocarcinoma subtypes provided additional information on risk for disease recurrence compared with FR⁺CTC or adenocarcinoma subtype alone.

Conclusion

Our study demonstrated that the preoperative FR⁺CTC level was a potential predictor for the prognosis of NSCLC patients underwent surgery. Further, when preoperative FR⁺CTC level is considered together with primary tumor proliferation characteristics, its prognostic value supplements that of these conventional pathological features.

Circulating tumor cells detected only after surgery for non-small cell lung cancer: is it a predictor of recurrence?

Background

Surgical manipulation of a tumor can lead to shedding of tumor cells that can enter the circulation and lead to metastasis. The present study evaluated the clinical relevance of circulating tumor cells (CTCs) that were identified immediately after non-small cell lung cancer resection in patients without preoperative CTCs, and whether postoperative CTC detection was associated with recurrence.

Methods

Immediate preoperative testing for CTCs was performed for 147 patients with pulmonary nodules. This study included 81 lung cancer patients (55.1%) with negative preoperative results for CTCs and who completed postoperative testing for CTCs. The clinical relevance of postoperative CTC detection was evaluated based on the clinicopathological characteristics and recurrence patterns.

Results

Among the eligible patients, the postoperative CTC results were none detected in 58 patients (71.6%, “Group N”), only a single CTC detected in 6 patients (7.4%, “Group S”), and CTC clusters detected in 17 patients (21.0%, “Group C”). The presence of postoperative CTCs was associated with tumor vessel invasion, lymph duct invasion, and pleural invasion. Distant metastasis was very common in cases with postoperatively detected CTC clusters. The 2-year recurrence-free survival rates were 94.6% for Group N, 62.5% for Group S, and 52.9% for Group C (P<0.01). Multivariate analysis revealed that recurrence was independently related to the postoperative detection of single CTCs and CTC clusters.

Conclusions

In cases without preoperative CTCs, we postoperatively detected CTCs and the postoperative CTC results were an independent predictor of recurrence.

Prognostic significance of spread through air spaces in pulmonary metastases from colorectal cancer

OBJECTIVES

Surgical resection for pulmonary metastases from colorectal cancer could provide long-term survival in selected patients, and it is commonly performed in practice. However, surgical margin relapse sometimes occurs and is a problematic issue to resolve. Spread through air spaces (STAS) is one of the invasion forms in primary lung cancer and is associated with local recurrence and a poor prognosis. The aim of this study was to evaluate the prognostic significance of STAS for pulmonary metastases from colorectal cancer and to assess the predictability of STAS with preoperative clinical information.

METHODS

A total of 96 pulmonary metastatic lesions from colorectal cancer in 37 patients who underwent metastasectomy at our institution from January 2008 to December 2013 were retrospectively analyzed.

RESULTS

STAS was identified in 41.6 % of the 96 lesions. Surgical margin relapse was found in 8 lesions (8.3 %) from 7 patients (18.9 %). The distance of STAS was identified as an independent risk factor for surgical margin relapse on multivariable analysis (p =  0.033). The patients with STAS showed significantly worse overall survival than those without (5-year overall survival rate: 30.3 % vs. 76.9 %; p =  0.002). On multivariable analysis, patients with STAS had a significantly higher risk of death than those without (p =  0.019). An elevated pre-metastasectomy serum carcinoembryonic antigen level was independently correlated with STAS on multivariable analysis (p =  0.049).

CONCLUSION

STAS was related to a poor prognosis and surgical margin relapse in pulmonary metastases from colorectal cancer.

Possible role of circulating tumor cells in early detection of lung cancer

The prognosis of lung cancer varies highly depending on the disease stage at diagnosis, from a 5-year survival rate close to 90% in stage I, to 10% or less in stage IV disease. The enhancement of early diagnosis of this malignancy is mandatory to improve prognosis, because lung cancer patients stay long asymptomatic or few symptomatic after disease onset. Nowadays, liquid biopsy has emerged as a minimally-invasive tool to address the urgent need for real time monitoring, stratification, and personalized treatment of malignancies, including lung cancer. Liquid biopsy refers to a class of biomarkers, including circulating tumor cells (CTCs), cell-free circulating tumor DNA (ctDNA) and tumor-derived extracellular vesicles (tdEV). Since CTCs represent a crucial step in disease progression and metastasis, we reviewed here the scientific literature about the use of CTCs in early diagnosis of lung cancer; different techniques, and different strategies (e.g., source of analysis sample or high-risk groups of patients) were discussed showing the potential of implementing liquid biopsy in the clinical routine of non-metastatic lung cancer.

Postoperative atrial fibrillation does not impact on overall survival after esophagectomy in patients with thoracic esophageal cancer: results from a randomized, double-blind, placebo-controlled trial

Background: Administration of landiolol hydrochloride was found to be associated with reduced incidence of atrial fibrillation (AF) after esophagectomy for esophageal cancer in our previous randomized controlled trial (RCT). In addition, reduced incidence of AF was associated with reduction of other complications. Meanwhile, the effects of postoperative AF and other complications on long-term survival following esophagectomy are not well understood.

Materials and Methods: Between March 2014 and January 2016, 100 patients with esophageal cancer were registered in an RCT trial and randomly allocated to receive either administration of landiolol or a placebo. We analyzed data from this RCT to better understand the effect of postoperative AF and severe associated complications on overall survival (OS) after esophagectomy for cancer. We also examined whether prophylactic administration of landiolol hydrochloride directly affects prolonged survival in patients with esophageal cancer.

Results: The five-year rates of OS in the patients with and without AF were 60%, and 68.6%, respectively, there was no significant difference (P = 0.328). Five-year rates of OS of the patients with and without severe complications were 64.6%, and 67.5%, respectively (P = 0.995). The five-year rates of OS in the placebo and landiolol groups were 65.8% and 68%, respectively (P = 0.809). In multivariate analysis, high stage (stage III/IV) alone was an independent prognostic factor for esophageal cancer patients following esophagectomy.

Conclusions: New-onset AF and the other severe complications were not associated with poorer long-term survival following esophagectomy. In addition, administration of landiolol hydrochloride after esophagectomy did not contribute to prolonging the OS.

Cluster circulating tumor cells in surgical cases of lung cancer

OBJECTIVES

A cancer lesion sheds tumor cells into the circulating blood as circulating tumor cells (CTCs). Since cluster CTCs have been considered as precursor lesions of metastasis, their clinical implication was investigated in this study according to the preoperative status of cluster CTC detection in surgical cases of clinically early-stage lung cancer.

METHODS

Among 104 surgical patients of early-stage lung cancer, CTCs were extracted from the peripheral blood before surgery using a micro-pore size selection method (ScreenCell^®) and diagnosed microscopically. Implications of detecting cluster CTC were assessed according to the prognosis and clinicopathological characteristics.

RESULTS

The status of CTC detection was not detected in 77 cases (74.0%), single CTC only detection in 7 cases (6.7%), and cluster CTC detected in 20 cases (19.2%). Patients with cluster CTCs exhibited significantly lower recurrence-free survival and overall survival than did patients of other groups. In addition, in hazard ratio analysis, the hazard ratios were independent of other predictors of poor prognosis, and detection of cluster CTCs was associated with predictors of poor prognosis.

CONCLUSION

Cluster CTCs were detected in cases where the original lung cancer lesion had clinical predictors of poor prognosis and were independent negative predictors of survival.

Analysis of Released Circulating Tumor Cells During Surgery for Non-Small Cell Lung Cancer

PURPOSE

Tumor cells from patients with lung cancer are expelled from the primary tumor into the blood, but difficult to detect in the peripheral circulation. We studied the release of circulating tumor cells (CTCs) during surgery to test the hypothesis that CTC counts are influenced by hemodynamic changes (caused by surgical approach) and manipulation.

EXPERIMENTAL DESIGN

Patients undergoing video-assisted thoracic surgery (VATS) or open surgery for (suspected) primary lung cancer were included. Blood samples were taken before surgery (T0) from the radial artery (RA), from both the RA and pulmonary vein (PV) when the PV was located (T1) and when either the pulmonary artery (T2 open) or the PV (T2 VATS) was dissected. The CTCs were enumerated using the CellSearch system. Single-cell whole-genome sequencing was performed on isolated CTCs for aneuploidy.

RESULTS

CTCs were detected in 58 of 138 samples (42%) of 31 patients. CTCs were more often detected in the PV (70%) compared with the RA (22%, P < 0.01) and in higher counts (P < 0.01). After surgery, the RA but not the PV showed less often CTCs (P = 0.02). Type of surgery did not influence CTC release. Only six of 496 isolated CTCs showed aneuploidy, despite matched primary tumor tissue being aneuploid. Euploid so-called CTCs had a different morphology than aneuploid.

CONCLUSIONS

CTCs defined by CellSearch were identified more often and in higher numbers in the PV compared with the RA, suggesting central clearance. The majority of cells in the PV were normal epithelial cells and outnumbered CTCs. Release of CTCs was not influenced by surgical approach.

Tumor-proximal liquid biopsy to improve diagnostic and prognostic performances of circulating tumor cells

Circulating tumor cell (CTC) detection and numeration are becoming part of the common clinical practice, especially for breast, colon, and prostate cancer. However, their paucity in peripheral blood samples is an obstacle for their identification. Several groups have tried to improve CTC recovery rate by developing highly sensitive cellular and molecular detection methods. However, CTCs are still difficult to detect in peripheral blood. Therefore, their recovery rate could be increased by obtaining blood samples from vessels close to the drainage territories of the invaded organ, when the anatomical situation is favorable. This approach has been tested mostly during tumor resection surgery, when the vessels nearest to the tumor are easily accessible. Moreover, radiological (including echo‐guided based and endovascular techniques) and/or endoscopic routes could be utilized to obtain CTC samples close to the tumor in a less invasive way than conventional biopsies. The purpose of this article is to summarize the available knowledge on CTC recovery from blood samples collected close to the tumor (i.e., in vessels located in the drainage area of the primary tumor or metastases). The relevance of such an approach for diagnostic and prognostic evaluations will be discussed, particularly for pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, and non‐small‐cell lung cancer.

Effect of Vein-First vs Artery-First Surgical Technique on Circulating Tumor Cells and Survival in Patients With Non-Small Cell Lung Cancer: A Randomized Clinical Trial and Registry-Based Propensity Score Matching Analysis

Importance

It is important to develop a surgical technique to reduce dissemination of tumor cells into the blood during surgery.

Objective

To compare the outcomes of different sequences of vessel ligation during surgery on the dissemination of tumor cells and survival in patients with non-small cell lung cancer.

Design, Setting, and Participants

This multicenter, randomized clinical trial was conducted from December 2016 to March 2018 with patients with non-small cell lung cancer who received thoracoscopic lobectomy in West China Hospital, Daping Hospital, and Sichuan Cancer Hospital. To further compare survival outcomes of the 2 procedures, we reviewed the Western China Lung Cancer database (2005-2017) using the same inclusion criteria.

Interventions

Vein-first procedure vs artery-first procedure.

Main Outcomes and Measures

Changes in folate receptor-positive circulating tumor cells (FR+CTCs) after surgery and 5-year overall, disease-free, and lung cancer-specific survival.

Results

A total of 86 individuals were randomized; 22 patients (25.6%) were younger and 64 (74.4%) older than 60 years. Of these, 78 patients were analyzed. After surgery, an incremental change in FR+CTCs was observed in 26 of 40 patients (65.0%) in the artery-first group and 12 of 38 (31.6%) in the vein-first group (P = .003) (median change, 0.73 [interquartile range (IQR), -0.86 to 1.58] FU per 3 mL vs -0.50 [IQR, -2.53 to 0.79] FU per 3 mL; P = .006). Multivariate analysis confirmed that the artery-first procedure was a risk factor for FR+CTC increase during surgery (hazard ratio [HR], 4.03 [95% CI, 1.53-10.63]; P = .005). The propensity-matched analysis included 420 patients (210 with vein-first procedures and 210 with artery-first procedures). The vein-first group had significantly better outcomes than the artery-first group for 5-year overall survival (73.6% [95% CI, 64.4%-82.8%] vs 57.6% [95% CI, 48.4%-66.8%]; P = .002), disease-free survival (63.6% [95% CI, 55.4%-73.8%] vs 48.4% [95% CI, 40.0%-56.8%]; P = .001), and lung cancer-specific survival (76.4% [95% CI, 67.6%-85.2%] vs 59.9% [95% CI, 50.5%-69.3%]; P = .002). Multivariate analyses revealed that the artery-first procedure was a prognostic factor of poorer 5-year overall survival (HR, 1.65 [95% CI, 1.07-2.56]; P = .03), disease-free survival (HR, 1.43 [95% CI, 1.01-2.04]; P = .05) and lung cancer-specific survival (HR = 1.65 [95% CI, 1.04-2.61]; P = .03).

Conclusions and Relevance

Ligating effluent veins first during surgery may reduce tumor cell dissemination and improve survival outcomes in patients with non-small cell lung cancer.

Trial Registration

ClinicalTrials.gov identifier: NCT03436329.

Minimal dosing of leukocyte targeting TRAIL decreases triple-negative breast cancer metastasis following tumor resection

Surgical removal of the primary tumor is a common practice in breast cancer treatment. However, postsurgical metastasis poses an immense setback in cancer therapy. Considering that 90% of cancer-related deaths are due to metastasis, antimetastatic therapeutic strategies that can target disseminating tumor cells in the circulation before they can form secondary tumors hold preclinical and clinical potential for cancer patients. Our current work uses a liposomal formulation functionalized with the adhesion receptor E-selectin and the apoptosis-inducing ligand TNF (tumor necrosis factor)-related apoptosis-inducing ligand (TRAIL) to reduce metastasis following tumor resection in an aggressive triple-negative breast cancer (TNBC) mouse model. We demonstrate that minimal administration of E-selectin-TRAIL liposomes can target metastasis in a TNBC model, with primary tumor resection to mimic clinical settings. Our study indicates that TRAIL liposomes, alone or in combination with existing clinically approved therapies, may neutralize distant metastasis of a broad range of tumor types systemically.

Perioperative Administration of an Intravenous Beta-Blocker Landiolol Hydrochloride in Patients with Lung Cancer: A Japanese Retrospective Exploratory Clinical Study

Beta-blockers have been reported to improve prognosis for various cancers, but the usefulness of perioperative administration remains unclear. To assess the efficacy of perioperative administration of landiolol hydrochloride, an intravenous beta-blocker, for lung cancer, we conducted a single-center, retrospective study. This study included patients who participated in a research conducted by Nippon Medical School Hospital from August 2012 to November 2013. The main selection criteria were males and females younger than 85 years old who have undergone anatomic lung resection for lung malignancies. Fifty-seven patients, 28 in the landiolol group and 29 in the control group, were included. The postoperative relapse-free survival rate at 2 years was 0.89 (95% CI, 0.78–1.01) in the landiolol group and 0.76 (95% CI, 0.60–0.91) in the control group (Chi-squared test; P = 0.1828). The relapse-free survival rate tended to be higher in the landiolol group than in the control. Hazard ratio for relapse-free survival in the landiolol group compared to the control was 0.41 (95% CI, 0.13–1.34), demonstrating that relapse free survival was prolonged in the landiolol group (log-rank test; P = 0.1294). It was suggested that relapse-free survival was prolonged when landiolol hydrochloride was administered from the induction to completion of anesthesia. Further studies are needed to confirm our findings.

Analysis of Cell-Free DNA to Assess Risk of Tumoremia Following Endoscopic Ultrasound Fine-Needle Aspiration of Pancreatic Adenocarcinomas

BACKGROUND & AIMS

Cellular and nuclear material from tumors disseminates into the bloodstream (tumoremia), but it is not clear whether medical procedures cause release of this material or contribute to formation of metastases. We performed a prospective study of blood samples from patients with pancreatic adenocarcinoma (PDAC) to determine whether endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) associates with markers of tumoremia.

METHODS

We obtained peripheral blood from 104 patients (35 with PDAC) before and after EUS-FNA of primary tumors; blood samples from 69 healthy individuals were used as controls. Plasma concentrations of cell-free DNA (cfDNA) were measured, and cfDNA and primary tumor samples were analyzed to detect activating mutations in KRAS. Potential development of tumoremia was defined by an increase in cfDNA of 2-fold or more, and/or detection of mutant KRAS in samples collected after FNA from patients whose blood samples did not contain detectable mutant KRAS before FNA.

RESULTS

Peripheral blood concentrations of cfDNA were 1200 ng/ml (500-3300 ng/ml) before FNA vs 1400 ng/ml (900-4000 ng/ml) after FNA (P = .391). Tumoremia was detected in 10/35 patients (28.6%): 7 patients had a ≥2-fold increase in cfDNA concentration (20.6%) and 3 patients had circulating tumor DNA with KRAS mutations after FNA that were not detected before FNA (8.8%). New distant metastases were detected in 1.3 ± 0.82 patients with tumoremia vs 0.64 ± 0.81 without (P = .0375). Overall mortality did not differ significantly between patients with tumoremia (10/10 deaths, 100%) vs those without (19/25 deaths, 76%) nor did survival times of deceased patients (13.3 months for patients with tumoremia; range, 5.8-14.9 months vs 11.1 months for patients without tumoremia; range, 5.5-14.5 months). However, 6 patients without tumoremia were alive at a mean 23.9 months after EUS-FNA (range, 19.9-25 months after EUS-FNA) vs none of the patients with tumoremia.

CONCLUSION

In patients with PDAC, EUS-FNA associates with increased plasma concentration of cfDNA and increased detection of mutant KRAS after the procedure (markers of tumoremia and possible new distant metastasis). Although levels of cfDNA and activating mutations in KRAS are logical markers of tumoremia, they may not serve as the ideal biomarkers of this process. These findings are preliminary and do not indicate a need to modify current practice, yet further studies are needed.

Intraoperative detection of circulating tumor cells in pulmonary venous blood during metastasectomy for colorectal lung metastases

Circulating tumor cells (CTC) have been studied extensively in various tumor types and are a well-established prognosticator in colorectal cancer (CRC). This is the first study to isolate CTC directly from the tumor outflow in secondary lung tumors. For this purpose in 24 patients with CRC who underwent pulmonary metastasectomy in curative intent blood was drawn intraoperatively from the pulmonary vein (tumor outflow). In 22 samples CTC-enumeration was performed using CellSieve-microfilters and immunohistochemical- and Giemsa-staining. Additionally 10 blood samples were analyzed using the CellSearch-System. We could isolate more CTC in pulmonary venous blood (total 41, range 0-15) than in samples taken from the periphery at the same time (total 6, range 0-5, p = 0.09). Tumor positive lymph nodes correlated with presence of CTC in pulmonary venous blood as in all cases CTC were present (p = 0.006). Our findings suggest a tumor cell release from pulmonary metastases in CRC and a correlation of CTC isolated from the tumor outflow with established negative prognostic markers in metastasized CRC. The presented data warrant further investigations regarding the significance of local tumor compartments when analyzing circulating markers and the possibility of tumor cell shedding from secondary lung tumors.

Pleural lavage cytology after lung resection in patients with non-small cell lung cancer and the feasibility of 20 mL saline solution

BACKGROUND

There are two issues to be discussed in pleural lavage cytology (PLC) for resected non-small cell lung cancer (NSCLC) whether it should be performed before (pre-PLC) or after (post-PLC) the lung resection and the dose of saline varies widely among the institutions.

METHODS

We retrospectively reviewed the clinical records of 466 consecutive patients who underwent a curative resection for NSCLC and received both a pre- and post- PLC using 20 mL of saline from January 2001 to December 2011.

RESULTS

There were 24/28 of positive pre- and post-PLC and 442/438 negative pre- and post-PLCs, respectively. Patients with a positive pre- or post-PLCs had significantly worse 5-year survival rates than those with negative results (pre-PLC positive/negative; 32.6%/69.9%, p = 0.001, post-PLC positive/negative; 21.4%/71.1%, p < 0.001, respectively). The post-PLC (p = 0.01) was an independent prognostic factor for the overall survival by a multivariate analysis, whereas the pre-PLC was not (p = 0.79).

CONCLUSIONS

The post-PLC was a more significant prognostic factor than the pre-PLC. Further, 20 mL of saline seemed feasible because of the consistent results compared to the past reports using a greater dose of saline for regarding the positive rates of the PLC and its prognostic significance.

Positive correlation between postoperative tumor recurrence and changes in circulating tumor cell counts in pulmonary venous blood (pvCTC) during surgical manipulation in non-small cell lung cancer

Background

In non-small cell lung cancer (NSCLC), circulating tumor cells (CTC) are shed and circulate to the peripheral blood through the pulmonary vein. Previously, CTC count in pulmonary venous blood (pvCTC) was shown to significantly increase after surgical manipulation. Therefore, we assessed the correlation between the changes in the pvCTC count (ΔpvCTC) and clinical outcomes.

Methods

Consecutive patients with peripheral-type, NSCLC, who underwent lobectomy or bi-lobectomy through open thoracotomy, were enrolled prospectively. Before and after lobectomy, 2.5 mL of blood was drawn from the associated lobar pulmonary vein (PV), and was served for the quantitative evaluation of CTC using the CellSearch^® system. The cut-off point of ΔpvCTC was determined according to clinical outcomes and ΔpvCTC using receiver operation characteristic (ROC) curve. Then the correlation between ΔpvCTC and clinical outcomes was evaluated by Kaplan-Meier analyses and log-rank test. In addition, the correlation between ΔpvCTC and perioperative variables was assessed.

Results

A total of 30 patients were enrolled, tumor recurrence occurred in 11 patients over a median follow-up of 64.4 months. Of these, 7 patients had distant metastasis and 4 had local recurrence. The median ΔpvCTC was 49 cells/2.5 mL, and pvCTC-count was increased during surgical manipulation in 24 patients (80%). We divided patients into two groups based on ΔpvCTC with the cut-off value as 119 cells/2.5 mL according to ROC curve. Significant shorter time to distant metastasis (TDM) (P=0.0123) was observed in high ΔpvCTC group (ΔpvCTC ≥119 cells/2.5 mL) than low ΔpvCTC group (ΔpvCTC <119 cells/ 2.5mL). Neither disease-free survival (DFS) nor overall survival (OS) was significantly correlated with ΔpvCTC.

Conclusions

Increasing pvCTC count during surgical manipulation was significantly correlated with postoperative distant metastasis in completely resected NSCLC patients. Significant shorter TDM was observed in patient with high ΔpvCTC group.

Correlation Between Postoperative Early Recurrence of Hepatocellular Carcinoma and Mesenchymal Circulating Tumor Cells in Peripheral Blood

BACKGROUND

Circulating tumor cells (CTCs) have been actively studied for their functions in hepatocellular carcinoma (HCC) recurrence. However, the relationship between circulating tumor cells subtypes and hepatocellular carcinoma recurrence is still unclear.

METHODS

CTCs were collected from the peripheral blood of 62 postoperative HCC patients. The CTCs were isolated with a filtration-based method. Multiplex fluorescence in situ hybridization was used to characterize the CTCs based on mRNA expression levels of epithelial and mesenchymal markers.

RESULTS

Of the 62 HCC patients, 26 were diagnosed with early recurrence (ER) and 36 did not experience recurrence. Comparison between the recurrence group and the non-recurrence group showed the total number of CTCs, mesenchymal CTCs, and mixed CTCs in the recurrence group was significantly higher than in the non-recurrence group. Receiver operator characteristic (ROC) curve analysis was performed to define the positive cutoff values as follows: total number of CTCs ≥ 4, mesenchymal CTCs ≥ 1, and mixed CTCs ≥ 3. Analysis showed that portal vein tumor thrombus (hazard ratio [HR] = 2.905, P = 0.023) and mesenchymal CTC positivity (HR = 3.453, P = 0.007) were independent risk factors for ER. The correlation between the presence of mesenchymal CTCs and time to recurrence was further examined, and the results showed significantly shortened postoperative disease-free survival in patients positive for mesenchymal CTCs (P < 0.001).

CONCLUSIONS

HCC patients with positive peripheral mesenchymal CTCs have a more serious risk of ER, which could be a potential biomarker in HCC prognosis monitoring.

Molecular characterization of circulating tumor cells in lung cancer: moving beyond enumeration

Molecular characterization of tumor cells is a key step in the diagnosis and optimal treatment of lung cancer. However, analysis of tumor samples, often corresponding to small biopsies, can be difficult and does not accurately reflect tumor heterogeneity. Recent studies have shown that isolation of circulating tumor cells (CTCs) is feasible in non-small cell lung cancer patients, even at early disease stages. The amount of CTCs corresponds to the metastatic potential of the tumor and to patient prognosis. Moreover, molecular analyses, even at the single-cell level, can be performed on CTCs. This review describes the technologies currently available for detecting and capturing CTCs, the potential for downstream molecular diagnostics, and the clinical applications of CTCs isolated from lung cancer patients as screening, prognostic, and predictive tools. Main limitations of CTCs are also discussed.

A no-touch technique for pulmonary wedge resection of lung cancer

OBJECTIVE

Many of the surgical patients with lung cancer die by metastasis originated from circulating tumor cells (CTCs) which are seeds of metastases. A ring-shaped catching forceps, which generates the great pressure by compression, may reduce the risk of tumor cell spreading. Here, we investigated the efficacy of such forceps based on CTC occurrence.

METHODS

Twenty-three patients with clinical stage IA lung cancer who underwent a pulmonary wedge resection were investigated in a clinical-pathological manner. They were divided into those treated using ring forceps catching without tumor release (R group) (n = 16) and non-complete use of ring forceps (N group) (n = 7), then were determined circulating tumor cells (CTCs).

RESULTS

Radiographic findings, tumor location, pathological diagnosis, and stapling method were not significantly different between the groups. The risk of detection of CTCs after surgery was significantly lower in group R (12.5 vs. 85.7%, p = 0.02), whereas there were no significant differences found in risk of negative-stapled margin cytology, pre-OP CTC detection, V (+), Ly (+), and Pl (+).

CONCLUSIONS

Patients who underwent pulmonary wedge resection of lung cancer had low chance of CTC detection after surgery when they were treated with ring forceps without tumor release, which might become a no-touch isolation technique.

A Prospective Study of Loose Tissue Fragments in Non-Small Cell Lung Cancer Resection Specimens: An Alternative View to "Spread Through Air Spaces"

The World Health Organization Classification of Lung Tumors considers "Spread Through Air Spaces" a form of invasion in lung adenocarcinoma. The recently described spread of free-floating cell clusters during lung specimen sectioning, otherwise known as "Spread Through A Knife Surface," represents an ex vivo artifact. The purpose of this study was to prospectively investigate the presence and frequency of these free-floating tumor cell clusters in surgically resected lung cancer specimens and their possible relation to gross examination procedures. A prospective, multi-institutional study of non-small cell lung cancer resection specimen was undertaken. At prosection the first cut was made with a clean knife; the second cut was made in a parallel plane to the first. Four tissue blocks were taken from upper and lower parts of first and second cuts. Hematoxylin and eosin-stained slides were examined for displaced benign and/or malignant tissue fragments. Forty-four resection specimens were studied. The mean number of tumor clusters for blocks 1 to 4 was 0.36, 1.44, 1.86, and 1.95, respectively, and for benign fragments was 0.11, 0.11, 0.13, and 0.25, respectively. Almost all cell clusters were intra-alveolar. Comparison of tumor cell clusters in block 1 with blocks 2 to 4 was significant with P-values (Friedman test for repeated measures 0.03) 0.031, 0.02, and 0.05, respectively. Overall 93% of the loose tissue fragments could be explained by mechanical forces associated with tissue handling. While the 2015 World Health Organization Classification of Lung Tumors recognizes Spread Through Air Spaces as a form of lung cancer invasion, such is debatable and in many instances likely represents mechanical artifact, including dissemination along the prosecting knife blade.

Does lung cancer surgery cause circulating tumor cells?-A multicenter, prospective study

BACKGROUND

Cancer relapse is caused by residual isolated tumor cells (ITCs) remaining in the body after surgery. It is speculated that surgical manipulation may cause circulating tumor cells (CTCs) which are the origin of ITCs in the body. The occurrence of CTCs in surgical patients with non-small cell lung cancer (NSCLC) has been shown in retrospective observation, but not prospectively, thus we conducted a multicenter prospective study regarding the occurrence of CTCs by surgical manipulation.

METHODS

Patients with T1b-2N0M0 lung cancer were studied. Blood samples were collected from the peripheral artery in the operating room at both pre- and post-lobectomy to extract CTCs by a size selection method. The CTCs detection rate, pathological findings, and background of each patient were studied.

RESULTS

The histological diagnosis of 29 patients were adenocarcinoma in 24 patients, squamous cell carcinoma in 3 patients, and other types in 2 patients. The number of pre-CTCs positive patients was 13 and the number of post CTCs positive patients was 17. Among the 16 patients who were pre-CTCs negative, 4 patients showed post CTCs positive, while all pre-CTCs positive patients remained post-CTCs positive.

CONCLUSIONS

The likelihood of CTC dislodgement by surgical manipulation is indicated based on the result that CTCs were detected after lung cancer surgery, where there were no cases of pre-CTCs positive and post CTCs negative.

Circulating Tumor Cells: Moving Biological Insights into Detection

Circulating tumor cells (CTCs) have shown promising potential as liquid biopsies that facilitate early detection, prognosis, therapeutic target selection and monitoring treatment response. CTCs in most cancer patients are low in abundance and heterogeneous in morphological and phenotypic profiles, which complicate their enrichment and subsequent characterization. Several methodologies for CTC enrichment and characterization have been developed over the past few years. However, integrating recent advances in CTC biology into these methodologies and the selection of appropriate enrichment and characterization methods for specific applications are needed to improve the reliability of CTC biopsies. In this review, we summarize recent advances in the studies of CTC biology, including the mechanisms of their generation and their potential forms of existence in blood, as well as the current CTC enrichment technologies. We then critically examine the selection of methods for appropriately enriching CTCs for further investigation of their clinical applications.

The promise of circulating tumor cells for precision cancer therapy

The rapidly growing array of therapeutic options in cancer requires informative biomarkers to guide the rational selection and precision application of appropriate therapies. Circulating biomarkers such as circulating tumor cells have immense potential as noninvasive, serial 'liquid biopsies' that may be more representative of the complete spectrum of a patient's individual malignancy than spatially and temporally restricted tumor biopsies. In this review, we discuss the current state-of-the-art in the isolation and molecular characterization of circulating tumor cells as well as their utility in a wide range of clinical applications such as prognostics, treatment monitoring and identification of novel therapeutic targets and resistance mechanisms to enable real-time adjustments in the clinical management of cancer.

Optimizing the Detection of Circulating Markers to Aid in Early Lung Cancer Detection

Improving early detection of lung cancer is critical to improving lung cancer survival. Studies have shown that computerized tomography (CT) screening can reduce mortality from lung cancer, but this involves risks of radiation exposure and can identify non-cancer lung nodules that lead to unnecessary interventions for some. There is a critical need to develop alternative, less invasive methods to identify patients who have early-stage lung cancer. The detection of circulating tumor cells (CTCs) are a promising area of research, but current technology is limited by a low yield of CTCs. Alternate studies are investigating circulating nucleic acids and proteins as possible tumor markers. It is critical to develop innovative methods for early lung cancer detection that may include CTCs or other markers that are low-risk and low-cost, yet specific and sensitive, to facilitate improved survival by diagnosing the disease when it is surgically curable.

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Background

Convenient approaches for accurate biopsy are extremely important to the diagnosis of lung cancer. We aimed to systematically review the clinical updates and development trends of approaches for biopsy, i.e., CT-guided PTNB (Percutaneous Transthoracic Needle Biopsy), ENB (Electromagnetic Navigation Bronchoscopy), EBUS-TBNA (Endobroncheal Ultrasonography-Transbronchial Needle Aspiration), mediastinoscopy and CTC (Circulating Tumor Cell).

Methods

Medline and manual searches were performed. We identified the relevant studies, assessed study eligibility, evaluated methodological quality, and summarized diagnostic yields and complications regarding CT-guided PTNB (22 citations), ENB(31 citations), EBUS-TBNA(66 citations), Mediastinoscopy(15 citations) and CTC (19 citations), respectively.

Results

The overall sensitivity and specificity of CT-guided PTNB were reported to be 92.52% ± 3.14% and 97.98% ± 3.28%, respectively. The top two complications of CT-guided PTNB was pneumothorax (946/4170:22.69%) and hemorrhage (138/1949:7.08%). The detection rate of lung cancer by ENB increased gradually to 79.79% ± 15.34% with pneumothorax as the top one complication (86/1648:5.2%). Detection rate of EBUS-TBNA was 86.06% ± 9.70% with the top three complications, i.e., hemorrhage (53/8662:0.61%), pneumothorax (46/12432:0.37%) and infection (34/11250:0.30%). The detection rate of mediastinoscopy gradually increased to 92.77% ± 3.99% with .hoarseness as the refractory complication (4/2137:0.19%). Sensitivity and specificity of CTCs detection by using PCR (Polymerase Chain Reaction) were reported to be 78.81% ± 14.72% and 90.88% ± 0.53%, respectively.

Conclusion

The biopsy approaches should be chosen considering a variety of location and situation of lesions. CT-guided PTNB is effective to reach lung parenchyma, however, diagnostic accuracy and incidence of complications may be impacted by lesion size or needle path length. ENB has an advantage for biopsy of smaller and deeper lesions in lung parenchyma. ENB plus EBUS imaging can further improve the detection rate of lesion in lung parenchyma. EBUS-TBNA is relatively safer and mediastinoscopy provides more tissue acquisition and better diagnostic yield of 4R and 7th lymph node. CTC detection can be considered for adjuvant diagnosis.